Attorney-General Mark Dreyfus has ordered the Commonwealth to drop the prosecution of lawyer Bernard Collaery, four years after he was charged with conspiring to release classified information about an alleged spying operation in East Timor

Mr Collaery was charged in 2018 for allegedly helping his client, an ex-spy known only as Witness K, to reveal details of the classified ASIS mission.

The Canberra lawyer was facing the prospect of jail, with his trial date set for October 24 in the ACT Supreme Court.

But Mr Dreyfus confirmed this afternoon that he had now determined the Commonwealth prosecution should end.

"In taking this decision, I have had careful regard to our national security, our national interest and the proper administration of justice."

Mr Dreyfus said the decision to discontinue the prosecution was informed by the government's commitment to protecting Australia's national interest, including its national security and relationships with close neighbours.

Human Rights Law Centre lawyer Kieran Pender, who has advocated over several years for the charges against Mr Collaery to be dropped, said the Attorney-General should be commended for the decision.

"This is an important day for Australian democracy. Bernard Collaery should never have been prosecuted. The Attorney-General has done the right thing and should be applauded for that," he said.

"There are many important stories that would never have been told were it not for the courageous actions of those who spoke up."

He said the dropping of charges against Mr Collaery was partially a result of the efforts of many legal professionals and activists since they were brought forward in 2018.

"The Attorney-General's decision is also a testament to the enduring work of lawyers, barristers, civil society organisations and activists who have fought this unjust prosecution, inside and outside the courtroom for more than four years," he said.

Following the decision, the Human Rights Law Centre is calling on the Attorney-General to similarly intervene in the ongoing prosecutions of David McBride, who blew the whistle on alleged war crimes by Australian soldiers in Afghanistan, and Richard Boyle, who spoke up about unethical practices at the Australian Taxation Office.

Mr Pender said whistleblowers like Mr Collaery, Mr McBride and Mr Boyle make Australia a better place, and their prosecutions should be dropped "as a matter of urgency."

"The Collaery, McBride and Boyle cases are vivid illustrations of the importance of robust whistleblower protections and the damage done to the public interest when whistleblowers are prosecuted rather than protected.

"Those robust protections do not exist in Australia today and it's beyond time that changed."

More to come.